With so many great free apps to choose from, who would have thought there was any reason to actually spend money on them, let alone ten dollars? It turns out there are indeed a bunch of apps worth paying for and here’s a list of some handy iPhone, Android, BlackBerry and Palm apps for summer vacation travelers or even those staying home that cost about as much as going to see a movie.

This versatile tool is not only for airplane travelers but even friends and family of travelers who want the latest status on a flight. It provides all kinds of real-time information including tracking maps and weather conditions at 35,000 feet. You can buy the basic version for $4.99 but for $9.99, FlightTrack will synchronize your itinerary with Tripit.

Backpacker magazine created this GPS-enabled backpacking app for anyone hiking, backpacking, mountain biking, trail running, mountaineering, or just looking to learn more about the space they were wandering around in. It offers tons of useful features like saving topographic maps, geotagging photos, keeping stats on your travels or just providing help for navigating trails. Just remember to bring along your solar charger so you don’t run out of juice.

With summer in full swing, it is time to get out and enjoy the local cuisine wherever you find yourself. Zagat To Go offers professional reviews of eateries in major cities worldwide. With easy offline browsing, maps (including a sweet augmented reality view), and filters, you can find the perfect place for the foodie within. It’s also available for BlackBerry, WinMo, PalmOS for $19.99.

If you are looking to get your body beach ready but don’t know where to start, then pick up FitnessBuilder for in depth, custom workout creation and tracking, goals, and exercise descriptions with videos and lots of pictures. FitnessBuilder can create the best set of exercises for burning fat or toning a specific muscle group without burning you out on one exercise, all while listening to your own music.

We know, the full version is more than $9.99 but if you are passionate about baseball then you won’t mind paying $14.99 for the full version of MLB At Bat 2010. The free version offers real-time news, scores, schedules, and standings. However, for $14.99 you can upgrade to the full version which buys you pitch-by-pitch updates, box scores and live game audio from the home or away announcers. Even more impressive is the live game video offered for select games daily. Forgot your team is playing today? No problem, because push notifications keep you in the action when you can’t be at the ballpark.

Headed to Munich this summer to take in the famous beer gardens and gawk at the impressive Neuschwanstein castle? Pick up Lonely Planet’s City Guide for Munich, or any other major world city, and instantly find places to stay, eat, and play. With built in maps and historical tidbits you can stay inconspicuous while wielding the complete power of the Lonely Planet’s years of experience without the weight and bulk of a book. And at just $5.99 per major city, it won’t cut into your lederhosen budget. While you’re being an undercover tourist, pick up the local language phrase book from lonely Planet for just $2.99/language.

It’s a little more expensive than most iPhone apps but CoPilot’s turn-by-turn directions app should keep you from resorting to asking for directions and is still way cheaper than a GPS. The new version, optimized for the iPhone 4, not only offers higher resolution images but provides turn-by-turn navigation even while you’re on the phone.

If you find yourself stargazing on a clear summer’s eve, invest in Distant Suns. With an augmented reality feature for the iPhone 3GS and 4, it couldn’t be easier to identify planets, stars, and constellations. This app even includes the mythology associated with constellations for your reading pleasure in addition to beautiful telescopic images of thousands of celestial bodies. Also of note is StarMap which shares many of the features of Distant Suns for $11.99 but pro versions offer advanced tools for amateur astronomers. If you are an Android user, check out Google SkyMap for free.

Whether you are a hypermiler trying to squeeze out every last mpg or just want to keep track of your vehicle related expenses, Gas Cubby will help you save a few bucks here and there during the drive-happy American summer. Whether you want to track gas mileage with detailed stats or keep track of vehicle maintenance, including service reminders for multiple cars, this app can help you.

Need to kill some time on a flight or while kicking back on a lazy summer Sunday? The board game Settlers of Catan is now transformed into a perfect i-version in Catan. Compete with up to three friends, or the AI, for the largest number of settlements, cities, roads, and other accomplishments in this modern classic strategy game.

The summer heat will likely have you looking everywhere for your next fix for cool treats. Making the search a cinch is Frozen Yogurt Locator which will point you towards the nearest frozen yogurt depending on your location. With options to search by chain or peer added locations, this app will meet your every froyo needs.

If Ten Dollars is Too Much to Pay
For a list of some fun apps that are free or only cost a dollar or two, check out this roundup of apps for weekend road trips.

Whether you’re staying home in your air conditioned living room watching baseball games on your new 3DTV or hitting the road, Retrevo can help you find the right gadgets to make your summer gadgetastic. You’ll find reviews and manuals for all the latest gear and gadgets including digital cameras, laptops, HDTV and more.

Retrevo.com is one of the largest consumer electronics review and shopping sites in the world, helping people decide what to buy, when to buy, and where to buy. Retrevo uses artificial intelligence to analyze and graphically summarize more than 50 million real-time data points from across the web to give shoppers the most comprehensive, unbiased, up-to-date product information they need to make smart, confident purchasing decisions for electronics.